In 1957, the Naval Security Group (NSG) established the Communication Security (COMSEC) Mobile Support Unit 9 at Sasebo, Japan.  In December of the same year, NSG established and commissioned the Naval Security Group Detachment (NSGD) Sasebo.

Initially the only mission for NSGD Sasebo was a high frequency direction finding (HFDF) operation with 11 personnel, including eight DF operators.  The site operated as part of the NSG’s Western Pacific (WESTPAC) HFDF network controlled from U.S. Naval Communications Facility Kami Seya (A). Initially, it was considered a temporary site until the NSG Activity at Hakata assumed Sasebo’s HFDF mission. 

The site was equipped with an AN/TRD-4 transportable DF station with a frequency range 540 kHz to 30 MHz. The antenna system consisted of two separate four element Adcock arrays, one of which had a range from 540 kHz to 10 MHZ and the other from 10 to 30 MHz. The DF receiver system included an R-390/URR HF radio communications receiver.

NSGD Sasebo sack just before commissioning sometime around the first week in December, 1957. The AN/TRD-4 antenna array was just installed. Photo courtesy of Richard Kivi (former CTR2)

Initially there were three DF operators stood the watch in a S44A/G shelter.  However, by 1959, as the mission grew, 20 manual Morse intercept operators were added to the team of HFDF operators and by 1962, the team grew between 30 and 40 NSG personnel.  In additional to the Navy team, there was also a small Army contingent.   By this time, not only were they responsible for DF operations and radio intercept, but maintaining field telephone communications.

Snort Ortlieb during Sasebo HFDF installation. The box in the backgroiund contained the AN/TRD-4. Note the emergency diesel generator building. The system was operational in approximately four days from installation. Photo courtesy of Richard Kivi, December, 1957

In September, 1964, COMSEC Support Unit 3 in Sasebo was disestablished.  Four years later in July 1968, NSGD Sasebo was deactivated and the station ceased operations. This “temporary site” operated for 10 years and seven months.

(A) On January 15, 1960 the U.S. Naval Communications Facility Kami Seya, Japan became the U.S. Naval Security Group Activity (NSGA), Kami Seya with approximately 1,500 people assigned.

CWO Shorty Allen, OIC. Photo courtesy of James Butler (former CTR2)

Some of the first to be stationed at NSDG Sasebo:

Andy Anderson 
Hank Aldredge, CTC
Jack W. Archebelle
*Tom A. “Shotgun” Bird
R. C. Britton
*James Butler
*A. C. Carlson
Richard “Dick” Conrad
Truman H. Cooper
Paul E. Duprey
Jim Exley
Joseph Foley
*Cal Fulmer
Bernie Gelotti
Jerry Gerken
Bruce W. Horncastle
*Dick Kivi
Ronald Koch
Gene Lathrum
Louie N. Martocci
*Bill Moore
*Ortlieb “Snort” Ortlieb
Joe A. Panza
Albert Pena
Dennis B. Tyler
J. F. Weiss
*Woody Woodside
Johnny Zelsnack
Ibara Toshiyiki (house boy)

*Original 8 HFDF operators

CTC Hank Aldredge, Photo courtesy of James Butler


Sasebo, with a good natural harbor at the mouth of Omura bay, was a Japanese Naval base from 1896 until the end of WWII. Sasebo was a small village until 1868, but expanded rapidly after wars with China and Russia. The town was partially destroyed during WWII, but was revived as a commercial and fishing port.

Sasebo has been an important Naval base since 1883, when then Lieutenant Commander Heihachiro Togo nominated the tiny fishing village to be established as the nucleus of a mighty base for the Imperial Japanese Navy. On July 1, 1889, the

Sasebo Naval Station began operations as headquarters for the Imperial Japanese Navy’s Third Naval District. In 1904, ships of the Japanese Navy under Admiral Togo sailed from Sasebo to take on the Russian Baltic Fleet. Admiral Togo’s victory at the Battle of the Tsushima Straits is a classic engagement in Naval history.

The Imperial Japanese Navy employed some 50,000 people at the Sasebo Naval Arsenal at the peak of World War II, constructing and refitting destroyers, light cruisers, submarines and other various Naval vessels. The 21st Naval Air Arsenal, established jointly at Sasebo and Omura, produced a total of 966 aircraft.

On September 22, 1945, the 5th Marine Division landed at Sasebo, and in June 1946, U.S. Fleet Activities Sasebo was formally established.

Downtown Sasebo, Japan, 1958. Photo courtesy of James Butler

When war broke out in Korea four years later, Sasebo became the main launching point for the United Nations and U.S. Forces. Millions of tons of ammunition, fuel, tanks, trucks and supplies flowed through Sasebo on their way to U.N. Forces in Korea. The number of American military personnel in Sasebo grew to about 20,000.

After the Korean War ended, Japan established its Self Defense Forces, and Japan Maritime Self Defense Force ships began to homeport in Sasebo, as U.S. Fleet Activities Sasebo continued to support ships of the U.S. Seventh Fleet. Service Force ships as well as mine craft also made Sasebo their homeport.

Sasebo Naval Base

U.S. Fleet Activities Sasebo provided heavy support to the expanded Seventh Fleet during the years of war in Southeast Asia. Repair work completed by Japanese shipyards in Sasebo was then, and is still today, equal to the best in the world. Operations at U.S. Fleet Activities Sasebo were scaled back during the mid-1970s and the base was designated as a Naval Ordnance Facility, while fleet visits dwindled to a very low level.

On July 4, 1980 this trend was reversed.  U.S. Fleet Activities Sasebo regained its name and once again, Seventh Fleet ships were forward deployed to Sasebo.  U.S. Fleet Activities Sasebo is currently home to USS Bonhomme Richard (LHD 6), USS Ashland (LSD 48), USS Germantown (LSD 42), USS Green Bay (LPD 20), USS Warrior (MCM 10), USS Patriot (MCM 7), USS Pioneer (MCM 9), USS Chief (MCM 14) and some 5,900 military members and their families as part of the Forward Deployed Naval Forces.

U.S. Fleet Activities Sasebo played a vital logistics role in 1990-91 during Operation Desert Shield/Storm by serving as a supply point for ordnance and fuel for ships and Marines operating in the Persian Gulf theater.

Sasebo today

Today, as throughout its history, U.S. Fleet Activities Sasebo stands ready to support Seventh Fleet units as they continue to ensure peace and security in the Pacific region.

The Nautilus Institute